1. Field of the Invention
Aspects of the present invention relate to an image scanning apparatus and a method of scanning both sides of a printable medium using the image scanning apparatus, and more particularly, to an image scanning apparatus having an additional printable medium reversal tray that temporarily supports a printable medium to scan both sides of the printable medium, and a method of scanning both sides of the printable medium using the image scanning apparatus.
2. Description of the Related Art
Image scanning apparatuses scan an image which is formed on a printable medium, such as paper, a transparency sheet, etc. FIG. 1 is a lateral cross-sectional view of a conventional image scanning apparatus. While shown individually, the image scanning apparatus shown in FIG. 1 may be combined with other devices, such as printers, copiers, and facsimile machines to provide a multi-function apparatus.
Referring to FIG. 1, the conventional image scanning apparatus includes a feeder 10 where printable media P that are to be scanned are stacked and a discharge tray 30 where the printable media P are scanned are stacked. The feeder 10 and the discharge tray 30 are mounted on a main body 1.
The main body 1 includes a pick-up roller 11, a plurality of transport rollers 12, 13, 14, and 15, a pair of discharge rollers 20, and a scanning unit 50. The pick-up roller 11 picks up the printable media P sheet by sheet and transports the individual sheets of printable media P into the main body 1. The transport rollers 12, 13, 14, and 15 each includes a pair of rollers to transport the printable medium P that was picked up by the pick-up roller 11 through the main body 1 during a scanning operation. The pair of discharge rollers 20 discharges the printable medium P to the discharge tray 30 after the scanning operation. The scanning unit 50 scans images on the printable medium P. A platen glass 40, also known as a flatbed, supports the printable medium P when the printable medium P is scanned above the scanning unit 50.
A conventional method of scanning one side of a printable medium P and the other side of the printable medium P using the conventional image scanning apparatus having the above structure will now be described.
The operation of scanning the sides of the printable medium P begins when the printable medium P is picked up by the pick-up roller 11. Then, the printable medium P is transported through a moving path 16, as indicated by the solid arrows in FIG. 1, by the transport rollers 12, 13, and 14, and an image of the printable medium P is scanned while the printable medium P passes by the scanning unit 50. The scanned printable medium P is discharged to the discharge tray 30 by the pair of discharge rollers 20 after the printable medium P has passed through the transport rollers 15.
Then, in order to scan the other side of the printable medium P after the first side of the printable medium P has been scanned as described above, the rotation of the pair of discharge rollers 20 is stopped before the printable medium P completely passes the pair of discharge rollers 20. Afterwards, the printable medium P, a side of which has been scanned, is reversely transported in an opposite direction to the direction in which the printable medium P has been moving by reversely rotating the pair of discharge rollers 20 in a counterclockwise direction in FIG. 1. At this point, a path converting unit 21 guides the printable medium P that has been reversely transported to enter a duplex path 31 as indicated by the dotted arrows in FIG. 1.
The printable medium P enters the duplex path 31 and is transported by the transport rollers 12, 13, and 14 so that the other side of the printable medium P is scanned as the printable medium P passes by the scanning unit 50. Then, the printable medium P, both sides of which have been scanned, is discharged to the discharge tray 30 by the pair of discharge rollers 20 after passing through the transport rollers 15.
When a plurality of the printable media P are discharged to the discharge tray 30 after both sides of each of the printable media P have been scanned, the printable media P are stacked in a reverse order compared to the original order that the printable media P were stacked in while located the feeder 10. Thus, in order to stack the printable media P on the discharge tray 30 in the same original order as the printable media P were originally stacked on the feeder 10, the printable media P, both sides of which have been scanned, must be transported once more through the moving path 16 as indicated by the solid arrows.
In the conventional image scanning apparatus having the above-described structure, in order to scan both sides of the printable media P, the printable media P which have been discharged to the discharge tray 30 are re-fed by the pair of discharge rollers 20 that reversely rotate. At this point, due to a large inclination between the moving path and the duplex path 31, the printable media P may impact the duplex path 31 with excessive force. In particular, if the printable media P are thick, the printable media P may get damaged.
Also, when a large number of printable media P are discharged and stacked on the discharge tray 30, during the operation of scanning both sides of subsequent printable media P, the subsequent printable media P may get jammed in the body 1 of the conventional image scanning apparatus due to blockage by the stacked printable media P. Alternatively, the subsequent printable media may push the printable media P stacked on the discharge tray 30 off the discharge tray 30 due to interference between the subsequent printable media P being scanned and the printable media P stacked on the discharge tray 30.